Usability metrics that matter for your SaaS



Usability metrics are the metrics that help in measuring the usability of a product or service. Usability is all about how easy and delightful it is to use a website or mobile app by its users. Such metrics should be measured to quickly find what works for your customers and what doesn’t. It should be your primary method to understand how satisfied customers use your product or service. Good user experience ensures that the users would accomplish their tasks with the least effort and stay happy for a longer time.

Usability metrics help find, measure, and improve the usability of a product. They allow UX designers and development teams to know how your customers use your website or mobile app and recognize the pain points that diminish the customer experience. Furthermore, it helps identify improvements to enhance the user experience.

Why Should You Care About Usability Metrics?

Designers need to measure UX metrics to help reduce bounce rates and raise conversion rates. Insights from Usability Metrics help designers create a user-friendly product that allows users to complete their tasks without any hassles. In addition, usability metrics are a good indicator of whether a product will succeed or not.

Usability testing can help identify the areas where your product needs improvement and understand what features users find difficult to use or seem confusing. In the long run, they will also prove beneficial for your business as customers who have been using your product would be happier and feel a stronger connection with your product. This can help you understand how your users think and feel about your product. Development teams cannot overlook the importance of measuring these metrics as they offer valuable insights about user experience, behaviour, and product expectations.

Usability Metrics for SaaS

SaaS companies look forward to launching a product that has ease of use and ensures the highest level of UX. Measuring usability is essential for SaaS companies as customers satisfied with the product are more likely to continue using the service. Usability metrics can enable the company to identify how much time customers spend on the platform and what features they hardly use or find difficult to understand. The data collected from usability metrics based on the customer feedback and other relevant KPIs can help you make changes to your product accordingly.

There is no set standard for what usability metrics to measure. It depends on your customer’s needs and requirements. But specific metrics can be calculated to provide invaluable insights about your customers and their experience with your product or service. The ones that matter the most and are the top priority to SaaS companies are Usability Metric of Effectiveness, Efficiency, and Satisfaction.

Usability Metric for Effectiveness

The effectiveness of a product is determined by how successful users find it to accomplish their tasks and produce the intended outcomes. Therefore, the effectiveness metric of a system can be measured by calculating the Success Rate and the Number of Errors.

Success Rate

The success rate, also known as the completion rate, refers to the percentage of users who completed a particular task. Users are considered successful if they accomplish a specific task in a particular amount of time and with less effort. The success rate is a good indicator for measuring the effectiveness of an interface.

A success rate is calculated by:

(Number of Successful Completions / Total Number of Tasks) * 100

The success rate helps designers and researchers identify whether the system is simple enough for all users to complete their tasks. Conversely, if the success rates are too low, they might indicate that certain users find it challenging to use the product. According to a study, the average success rate is 78%, though it has been observed that the success rate is influenced heavily by the task’s context.

Number of Errors 

The Number of Errors refers to the number of times a user makes errors while using the system. The number of mistakes helps us identify whether the system prompts the right message at the right time to prevent errors. Furthermore, it can be a good indicator of whether a system is easy to use or not.

Errors are unintended actions and slips that cause a system to produce an incorrect result. These can be avoided if the product has been designed better, more reliable, and is user-friendly. Another reason for errors is users having different abilities and knowledge on how to use a specific product or what features they should use. This is why calculating the error rate can show designers where to look at and the direction they can take to improve it when designing their products.

The number of errors can be measured by:

Number of Errors committed / Total Number of Attempts made by the users

Estimating the error rate helps designers understand the areas of the interface that need to be improved.

Usability Metrics for Efficiency

Task Time

The efficiency of a product refers to the ease with which customers can complete their tasks using the product. Some customers may require more time than others for completing specific tasks. The task time is calculated by:

Task Time = End Time – Start Time

The usability metric of efficiency can be helpful for product managers as they would be able to identify the areas that need improvement. For example, if the Task Time is more than average, users are required to spend longer time on specific features. Users may take a long time to finish a task or not finish them at all because of low efficiency or lack of usability or simply because there are not enough resources for the system.

Time-Based Efficiency

The Time-Based Efficiency is calculated using the success rate and the task time measured.

time-based efficiency



N = The total number of tasks 

R = The total number of users

nij = The results of task ‘i’ by user ‘j‘. If the user has completed the task, then Nij = 1, if not, then Nij = 0

tij = The time spent by user ‘j’ to complete task ‘i’. If the task is not completed, time is measured until the user quits the task.

This metric shows the measurement of the time spent by the user to complete the task or speed of work. This metric is mainly used to understand whether your product provides enough resources for customers to complete assignments or requires more resources.

Relative Efficiency

The Relative Efficiency is calculated using the success rate ratio to the measured task time.

Relative efficiency is a good indicator of how effectively your system guides the users towards efficiently completing their tasks.

Usability Metric for Satisfaction

A user’s satisfaction in terms of ease of use, usefulness, and learnability of a product denotes the satisfaction rate of the product. The satisfaction measurement needs to be defined more accurately as it can vary from company to company based on their expectations, goals, and working environment. The satisfaction metric measures the user’s emotional response after completing a task on a product. There are numerous measures designers can utilize to determine user satisfaction.

Task Level Satisfaction

Satisfaction at the task level is measured by finding out the degree of satisfaction with each task in a product. The questionnaires employ the Likert scale rating method and ask users to rate each task. This method enables designers to create a list of tasks rated as being most satisfactory to those with the least satisfaction rating.

Single Ease Questions (SEQ)

Users’ satisfaction can be measured by asking them if they faced any difficulty while using a product. The SEQ is a single-question post-task questionnaire that helps designers know the users’ satisfaction.

Subjective Mental Effort Questionnaire (SMEQ)

Subjective mental effort questionnaire (SMEQ) is a single question survey that asks respondents to rate their subjective mental efforts associated with completing a task on a product.

After Scenario Questions (ASQ)

This questionnaire comprises three questions that assess how difficult a task was for the user in a usability test. It is simple and quantifies perceived usability ease.


NASA’s task load index is a tool for measuring the subjective mental effort of the users on a 7 point scale. It allows designers to measure and compare mental workload across different usability tasks.

The questionnaire is divided into two parts. The first part represents six subscales that enquire about the user’s experience. The second part lets the user convey their priorities for each task.

Usability Magnitude Estimation (UME)

UME is a standard applied to measure judgements of sensory stimuli. UME has been proven to be efficient and highly effective for comparing usability.

Test Level Satisfaction

Test level satisfaction measures the users’ overall ease of use in their usability tests. They are questionnaires shared with the users only after the test session.

System Usability Scale (SUS)

A system usability scale is a simple, ten-item Likert scale that gives a view of subjective assessments of usability. SUS is a manageable scale that can be administered to participants. It is also reliable on small sample sizes.

Software Usability Measurement Inventory (SUMI)

SUMI is a user survey created to measure the usability of computer software. Each survey question asks respondents to choose between different options.

Standardized User Experience Percentile Rank Questionnaire (SUPR-Q)

SUPR-Q is a survey designed to collect user experience information on a large scale. It provides a fast and efficient platform for designers to do a comparative usability study on various products or systems. The questions are scored on a 1-5 scale.

Questionnaire For User Interaction Satisfaction (QUIS)

The purpose of a QUIS is to give managers a tool for assessing the system and finding areas to improve on. In addition, it is a valid instrument for conducting comparative studies on usability.


The high competition in the Saas industry provides users with an abundance of choices that are bound to keep them spoiled. Therefore, analysing your users’ needs, desires, and preferences is essential to delivering quality products that consistently meet their expectations. 

Usability metrics in SaaS are crucial because they allow designers to get the details to improve their usability goals. In addition, products must hold a standard across all platforms because this ensures an improved user experience, thus creating satisfied customers.

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